Currently you must take out a Premium subsrcription if you want to access Spotify Connect (wireless connection to speakers, etc).
This really makes no sense, since it is still possible in the Free version of Spotify to listen via your computer or smartphone using headphones, or via a Hi-Fi amplifier and into good quality speakers, or via Bluetooth into other speakers, etc. But you cannot do this via Wi-Fi unless you have Spotify Connect active.
My request is to remove this silly restriction and make Spotify Connect available in the free version of Spotify too. Please vote for this if you agree.